AC power continues to drive the modern data centers underpinning the world's businesses and internet applications, with DC playing only a supporting role. But DC power has long been touted as a way to reduce the ridiculous amount of power consumed by these massive computing facilities, and a new study hopes to catalyze its widespread adoption... study comes from the Electric Power Research Institute (EPRI), a not-for-profit based in Palo Alto, California, and it details a set of experiments performed at a data center operated by Duke Power in Charlotte, North Carolina. With their experiments, Dennis Symanski and his team tried to balance the power to the servers equally between AC and DC sources, performing multiple load tests on each, with equipment in various states of operation (on, off, idle).
The results of six different tests show that the DC power system exhibited an energy savings ranging from 14.9 percent (when all servers and storage arrays were run at full power) to 15.8 percent (when the servers were turned on, but idle). On average, DC improved efficiency about 15.3 percent over AC systems.